collector hangs low

That is a common problem with those headers even back when they were designed and sold by Herb McCandless. I ran a set on a BB Scamp race car back in the early 90's. I always had trouble with the pass. side collector flange hanging up on my car trailer when I loaded it. The problem was that one of the collector flange bolts was pointing in the down position. Since this was a drag car I solved it by simply cutting off this part of the flange.